I have run sanitycheck.cgi in Bugzilla and getting following error message :

Bad value '0' found in longdescs.bug_idBad value '47739' found in longdescs.bug_idBad value '99999' found in longdescs.bug_idBad value '455505' found in longdescs.bug_idRemove invalid references to non existent bugs.

Bugs that have changes but no mail sent for at least half an hour: 45749 (as bug list).Send these mails.Checking for whines with non-existent users/groups.Non-existent group 618 for whine schedule 51Click here to remove old users/groups

Full result of running sanitycheck.cgi is diaplyed below:Bugzilla is checking the referential integrity of your database. This may take several minutes to complete.Errors, if any, will be emphasized like this. Depending on the errors found, some links will be displayed allowing you to easily fix them. Fixing these errors will automatically run this script again (so be aware that it may take an even longer time than the first run).OK, now running sanity checks.Checking references to classifications.id...... from products.classification_id.Checking references to keyworddefs.id...... from keywords.keywordid.Checking references to fielddefs.id...... from bugs_activity.fieldid.... from profiles_activity.fieldid.Checking references to flagtypes.id...... from flags.type_id.... from flagexclusions.type_id.... from flaginclusions.type_id.Checking references to bugs.bug_id...... from bugs_activity.bug_id.... from bug_group_map.bug_id.... from bugs_fulltext.bug_id.... from attachments.bug_id.... from cc.bug_id.... from longdescs.bug_id.Bad value '0' found in longdescs.bug_idBad value '47739' found in longdescs.bug_idBad value '99999' found in longdescs.bug_idBad value '455505' found in longdescs.bug_idRemove invalid references to non existent bugs.... from dependencies.blocked.... from dependencies.dependson.... from flags.bug_id.... from votes.bug_id.... from keywords.bug_id.... from duplicates.dupe_of.... from duplicates.dupe.Checking references to groups.id...... from bug_group_map.group_id.... from category_group_map.group_id.... from group_group_map.grantor_id.... from group_group_map.member_id.... from group_control_map.group_id.... from namedquery_group_map.group_id.... from user_group_map.group_id.... from flagtypes.grant_group_id.... from flagtypes.request_group_id.Checking references to namedqueries.id...... from namedqueries_link_in_footer.namedquery_id.... from namedquery_group_map.namedquery_id.Checking references to profiles.userid...... from profiles_activity.userid.... from profiles_activity.who.... from email_setting.user_id.... from profile_setting.user_id.... from bugs.reporter.... from bugs.assigned_to.... from bugs.qa_contact.... from attachments.submitter_id.... from flags.setter_id.... from flags.requestee_id.... from bugs_activity.who.... from cc.who.... from quips.userid.... from votes.who.... from longdescs.who.... from logincookies.userid.... from namedqueries.userid.... from namedqueries_link_in_footer.user_id.... from series.creator.... from watch.watcher.... from watch.watched.... from whine_events.owner_userid.... from tokens.userid.... from user_group_map.user_id.... from components.initialowner.... from components.initialqacontact.... from component_cc.user_id.Checking references to products.id...... from bugs.product_id.... from components.product_id.... from milestones.product_id.... from versions.product_id.... from group_control_map.product_id.... from flaginclusions.product_id.... from flagexclusions.product_id.Checking references to components.id...... from component_cc.component_id.... from flagexclusions.component_id.... from flaginclusions.component_id.Checking references to bug_status.value...... from bugs.bug_status.Checking references to resolution.value...... from bugs.resolution.Checking references to bug_severity.value...... from bugs.bug_severity.Checking references to op_sys.value...... from bugs.op_sys.Checking references to priority.value...... from bugs.priority.Checking references to rep_platform.value...... from bugs.rep_platform.Checking references to series.series_id...... from series_data.series_id.Checking references to series_categories.id...... from series.category.... from category_group_map.category_id.... from series.subcategory.Checking references to whine_events.id...... from whine_queries.eventid.... from whine_schedules.eventid.Checking references to attachments.attach_id...... from attach_data.id.... from bugs_activity.attach_id.Checking references to bug_status.id...... from status_workflow.old_status.... from status_workflow.new_status.Checking references to attachments.bug_id / attachments.attach_id...... from flags.bug_id / flags.attach_id.... from bugs_activity.bug_id / bugs_activity.attach_id.Checking references to components.product_id / components.id...... from bugs.product_id / bugs.component_id.... from flagexclusions.product_id / flagexclusions.component_id.... from flaginclusions.product_id / flaginclusions.component_id.Checking references to versions.product_id / versions.value...... from bugs.product_id / bugs.version.Checking references to milestones.product_id / Milestones.value...... from bugs.product_id / bugs.target_milestone.... from products.id / products.defaultmilestone.Checking profile logins.Checking cached vote counts.Checking keywords table.Checking cached keywords.Checking for flags being in the wrong product/component.Checking for bugs with no creation date (which makes them invisible).Checking for bugs with no entry for full text searching.Checking resolution/duplicatesChecking statuses/resolutionsChecking statuses/everconfirmedChecking votes/everconfirmedChecking for bad values in group_control_mapChecking for bugs with groups violating their product's group controlsChecking for unsent mailBugs that have changes but no mail sent for at least half an hour: 45749 (as bug list).Send these mails.Checking for whines with non-existent users/groups.Non-existent group 618 for whine schedule 51Click here to remove old users/groupsSanity check completed.